The effects of intromission frequency on successful pregnancy in the female rat

摘要: The copulatory pattern of several species rodents including the rat, mnouse, hamster, and deermuouse (Peroimyscus) includes a series mounts during which male briefly inserts penis into vagina but withdraws without ejaculating. Ejaculation occurs last insertion series, when intromission is maintained for longer period time. function pre-ejaculatory intromissions has previously been investigated from stantdpoint nmale. Beach'-3 postulated that each rat contributed an increment toward attainment ejaculatory threshold; studies developing this model have subsequently carried out.4--~0